The present invention relates to a particle beam irradiation system suitable for a particle beam treatment making use of a charged particle beam (ion beam) of protons or heavy ions. More particularly, the invention relates to a particle beam irradiation system capable of controlling changes in beam energy and realizing operation cycle updates in a short time, and to a method for operating the system.
The particle beam treatment is known as cancer radiotherapy whereby the affected part of a patient with a cancer is irradiated with an ion beam of protons or heavy ions for treatment. One method of ion beam irradiation is a scanning irradiation method.
Where a synchrotron is adopted as an ion beam generator for controlling changes in beam energy as required of the scanning irradiation method as a method for providing the control in a short time, there is available a multistage extraction control operation for bringing about irradiation with an ion beam at a plural energy stages within one operation cycle of the ion synchrotron, as disclosed in Japanese Patent No. 4873563, JP-2011-124149-A, and “Nuclear Instruments and Methods in Physics Research,” No. A624 (September 2010), pp. 33-38 (hereinafter, referred to as Non-patent Document 1).
Japanese Patent No. 2921433 and JP-2013-111406-A describe methods for irradiating with a beam a respiratory moving organ of which the affected part moves over time due to the patient's physiological activities such as respiration.